JPH04286287A - Brightness signal reproducing circuit holding compatibility at the time of reproducing between different video system and its method - Google Patents

Abstract

PURPOSE: To reproduce video signals without deteriorating the picture qualities of the signals with the existing VCR(video cassette recorder) by selecting one luminance signal processing circuit in accordance with the result of detected frequency-superimposed information. CONSTITUTION: When luminance signals recorded by the existing system are reproduced with an improved video signal recorder, whether the recorded video signals are recorded by the conventional system or an improved system is detected through a frequency-superimposed information detecting section 80. Then a selecting means selects the signal processing section using the existing system or another signal processing section using the improved system in accordance with the detected results. When the detecting section 80 detects frequency- superimposed information, on the other hand, a first selecting section 82 supplies the luminance signals to a frequency unfolding section 101 for processing and a second selecting section 200 selects one of the signals supplied from a memory section 91 and an adaptive peaking reproducing emphasis section 104 and supplies the selected signal to a luminance signal outputting section.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminance signal reproducing circuit and method for maintaining compatibility during reproduction between different video systems. In particular, the present invention is filed in the United States on August 17, 1990 by the Japanese applicant, No. 07/569,02.
A luminance signal reproducing circuit and its circuit for reproducing video tape recorded by a conventional video signal recording and reproducing system while maintaining compatibility with the system disclosed in No. 9 "Improved Video Signal Recording System" Regarding the method.

0002

2. Description of the Related Art Generally, in an existing video signal recording and reproducing device, when recording a composite video signal as shown in FIGS. is supplied to the emphasis section 2 to emphasize the high frequency components of the luminance signal. During playback, a de-emphasis unit 10 is used to restore the high-frequency components of the luminance signal emphasized during recording to the original signal.
Processed by This is shown in (A) and (B) in Figure 1.
Please refer to and briefly explain.

According to (A) in FIG. 1, the recording circuit of the existing video signal recording and reproducing device performs Y/Y when a video signal is input.
A luminance signal Y is separated through a C separation section 1, and this separated luminance signal Y is emphasized in an emphasis section 2 and then supplied to an FM modulation section 3.

[0004] The signal modulated from the FM modulator 3 is
The signal is amplified by the recording amplification section 4 and recorded on a video tape by the recording head 5. At this time, although not shown, the color signal separated by the Y/C separation section 1 is processed by the color signal processing section, combined with the luminance signal, and recorded. On the other hand, (B) in Figure 1
As shown in FIG. 1, the reproducing circuit of the existing video signal recording and reproducing apparatus reproduces the video signal recorded on the video tape through the reproducing head 6, and then reproduces the luminance signal through the standard luminance signal reproducing section 7. The reproduced luminance signal Y is limited by a limiter 8 and then demodulated by an FM demodulator 9. Further, this demodulated luminance signal is supplied to a de-emphasis section 10 in order to restore the signal emphasized by the recording circuit to the original signal. Next, in the composite video signal generation section 11 (not shown), the color signal from the color signal reproduction processing section and the de-emphasized luminance signal are combined to output a composite video signal Y+C.

However, as shown in FIGS. 2(A) and 2(B), the recording circuit and reproducing circuit of the improved video signal recording/reproducing apparatus to which the circuit of the present invention is applied does not include the recording circuit (A) in FIG. )
Unlike the case of the existing recording circuit and reproducing circuit shown in FIG. When reproduced, the luminance signal passes through the adaptive re-emphasis unit 23 after frequency unfolding. This will be explained briefly.

According to FIG. 2A, the composite video signal Y+
C passes through an A/D converter 21 and is separated into luminance and color signals by a Y/C separator 22. This separated luminance signal Y passes through the adaptive de-emphasis section 23 and then passes through the frequency superimposition section 24.
The frequency superimposed signal is output, and the frequency superimposed information recording section 25 inserts frequency superimposed information for separating the superimposed frequencies during reproduction into the horizontal synchronization signal Hsync. Next, the luminance signal into which the frequency superimposition information has been inserted is D/A converted by the D/A converter 26, and is recorded on the video tape through the recording head 27 together with the color signal through a series of steps not shown. On the other hand, as shown in FIG. 2B, in the reproducing circuit of the improved video signal recording and reproducing device to which the circuit of the present invention is applied, a luminance signal is reproduced by a standard luminance signal reproducing section 29 through a reproducing head 28. be done.

Thereafter, although not shown in FIG. 2A, in order to restore the luminance signal pre-emphasized during recording to its original state, a de-emphasis section 30 de-emphasizes the high-frequency side signal of the luminance signal. The de-emphasized luminance signal is FM demodulated (not shown), and the F
When the M-demodulated luminance signal is input to the A/D converter 31, the frequency superimposition information detector 32 detects the frequency superimposition information recorded by the frequency superimposition information recording section 25 when recording the video signal.

Next, the frequency unfolding section 33
Then, the frequency-superimposed signal is expanded according to the frequency-superimposed information detected by the frequency-superimposed information detection section 32. Thereafter, this unfolded signal is restored to the original signal via the adaptive re-emphasis section 34 and D
A desired luminance signal is output through the /A converter 35. Next, although not shown in FIG. 2B, the color signal from the color signal processing unit that processes the reproduced color signal and the luminance signal are combined in a composite video signal generation unit 36 to generate a composite video signal. Output Y+C.

Therefore, the video signal recorded by the recording circuit of the existing video signal recording and reproducing apparatus as shown in FIG. 1(A) can be converted into an improved video signal recording method as shown in FIG. 2(B). When reproducing using the reproducing circuit of the reproducing device, the recorded video signal goes through an improved video signal reproducing process in which the frequency unfolding section 33 unfolds the signal, so it is not possible to restore the original signal. Ta. In the end, the applicant's August 1, 1990 video signal recorded using the existing video signal recording and reproducing device was
Application No. 07/56 filed in the United States on the 7th
When trying to playback using the system disclosed in No. 9,029, the resolution that was originally recorded cannot be obtained, and complete compatibility cannot be maintained between different video signal recording and playback methods. has been pointed out.

0010

SUMMARY OF THE INVENTION Therefore, the present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide improved video signal recording and reproducing to which the circuit of the present invention is applied. By adding a circuit that can reproduce video signals recorded by different video signal recording methods while maintaining compatibility on the playback circuit side of the device, it is possible to reproduce different video signal recording methods in a single video signal recording and playback device. It is an object of the present invention to provide a luminance signal reproduction processing circuit which maintains compatibility during reproduction and allows a video signal recorded on a video tape to be reproduced on the screen as it is at the resolution at the time of recording.

[0011]

[Means for Solving the Problems] In order to achieve the above-mentioned object, when a video signal is recorded on a video tape, its luminance signal and synchronization signal are processed by an adaptive de-emphasis section, a frequency superposition section, and a frequency superposition information recording section. When recording and playing back video signals of a predetermined full bandwidth that are detected through a frequency superposition information detection unit, a frequency unfolding unit, and an adaptive re-emphasis unit and recorded in advance on a recording medium having a limited bandwidth. In a luminance signal reproducing circuit of a video signal reproducing device for reproducing a video signal, the circuit includes a luminance signal input section into which a luminance signal is input, and a luminance signal and a synchronization signal supplied from the luminance signal input section to generate frequency superimposition information. a frequency superimposition information detection section that detects whether the frequency superposition information detection section detects whether or not the frequency superposition information detection section is placed on the synchronization signal; a first selection section that selectively supplies a luminance signal according to the detection result from the frequency superposition information detection section; and the frequency superposition information detection section. an improved luminance signal processing section that processes the luminance signal using an improved video signal processing method if the frequency superimposition information is detected in the section; and an improved luminance signal processing section that processes the luminance signal using an improved video signal processing method; An existing luminance signal processing section that processes a luminance signal using a signal processing method, and output signals from the improved luminance signal processing section and the existing luminance signal processing section according to the detection results from the frequency superimposition information detection section are integrated. The second to select one signal
The present invention is characterized in that it includes a selection section and a luminance signal output section that outputs the luminance signal supplied from the second selection section.

[0012] Furthermore, in the reproduction method according to the present invention, when reproducing a video signal having a predetermined full bandwidth recorded in advance on a recording medium having a limited bandwidth, the reproduction method is such that when a video signal having a predetermined full bandwidth is reproduced on a recording medium having a limited bandwidth, the video signal is reproduced from the recording medium through a reproduction head. a step of inputting a luminance signal processed by a standard luminance signal regenerator that processes a video signal; a step of detecting whether frequency superimposition information is included in the input luminance signal; selecting one of the processing routes for the luminance signal, processing the luminance signal along the selected processing route for the luminance signal, and selecting one of the processing routes for the luminance signal according to the frequency superimposition information. The present invention is characterized in that it includes a process of selecting and outputting one of the luminance signals, thereby reproducing the luminance signals on a videotape recorded using an existing video signal recording method while maintaining compatibility.

[0013]

[Operation] In order to make the luminance signal compatible between different video systems, the reproducing circuit is connected to the improved luminance signal processing section in the VCR to which the circuit according to the present invention is applied, and the reproduction circuit is connected to the luminance signal processing section in the VCR that is improved to which the circuit according to the present invention is applied, video signals can be played back in a compatible manner.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a luminance signal reproducing circuit and method according to the present invention will be described in detail with reference to the accompanying drawings.

According to FIG. 3, the circuit for reproducing a luminance signal in a compatible manner between different video systems according to the present invention includes a luminance signal input section 70 that reproduces a luminance signal from a video tape (not shown) through a reproduction head. A standard luminance reproducing section reproduces only the luminance signal of the video signal, performs A/D conversion, and corrects it with respect to the time axis. Next, frequency superimposition information detection section 80
Now, it is detected whether the luminance signal output from the luminance signal input section 70 includes frequency superimposition information. Although the de-emphasis section 81 can be provided before the luminance signal input section 70, in this embodiment, the de-emphasis section 81 is provided after the frequency superposition information detection section 80, so that the luminance that has passed through the frequency superposition information detection section 80 Attenuates the high frequency components of the signal. The signal de-emphasized by this de-emphasis section 81 passes through a regenerative equalization amplifier 85 and then goes to a first selection section 82.
supplied to Further, if frequency superposition information is detected according to the detection result from the frequency superposition information detection section 80, the first selection section 82 selects and outputs the luminance signal in the improved luminance signal processing section 100, If not detected, the existing luminance signal processing section 90 selectively outputs the luminance signal.

Next, the improved luminance signal processing section 100
The signal processed by the existing luminance signal processing section 90 and the signal processed by the existing luminance signal processing section 90 are supplied to the second selection section 200.

The second selection section 200 selects one of the signals supplied from the existing luminance signal processing section 90 and the improved luminance signal processing section 100 according to the detection result from the frequency superimposition information detection section 80. Two signals are selectively output.

Next, the luminance signal output section 300
It receives the output from the selection section 200 and outputs a luminance signal.

FIG. 4 shows the operation of the luminance signal reproduction processing circuit that maintains reproduction compatibility between signal recording and reproduction methods between different video systems according to the present invention having the above-described configuration.
This will be explained in detail with reference to .

According to FIG. 4, when a video tape recorded by the existing method is played back by the improved video recording/playback apparatus to which the circuit of the present invention is applied, the played video signal is not shown in the figure. After being separated into luminance signals in the standard luminance reproducing section, the luminance signal Y is converted into a digital signal via the A/D converter 71, and this digitally converted signal is converted into a regular signal via the time base correction section (TBC) 75. After being aligned, all of the data signals and synchronization signals are supplied to the frequency superimposition information detection section 80. At this time, the data signal is the luminance signal,
Synchronization signal means a composite synchronization signal. The frequency superimposition information detection section 80 detects whether frequency superposition information exists in the composite synchronization signal. A detailed explanation thereof is disclosed in Korean Patent Application No. 90-17587 dated October 31, 1990, filed by the present applicant, and will therefore be omitted here.

At this time, since the luminance signal that has passed through the frequency superimposition information detection section 80 is a signal that has been pre-emphasized during recording, the high frequency side components are attenuated through the de-emphasis section 81. This de-emphasis section 81 is based on U.S. Patent Application No. 07/569,02 dated October 31, 1990.
As shown in FIG. 2(B) in No. 9, the A/D converter 31
However, in a preferred embodiment of the present invention, it is located after the frequency superimposition information detection section 80. Further, the luminance signal de-emphasized by the de-emphasis section 81 is supplied to a first selection section 82.
2 selects any one reproduction processing route through which the luminance signal input from the de-emphasis section 81 via the reproduction equalizer 85 is processed, according to the detection result of the frequency superimposition information detection section 80. If the input luminance signal is a luminance signal recorded using an existing method, the first selection section 82 performs noise attenuation during a still image in the memory section 91 and then supplies it to one stage of the second selection section 200 . In the case of a video signal recorded by the improved method, the frequency unfolding unit 1
Supply to 01.

[0022] Therefore, in the present invention, when a luminance signal recorded by the existing method is reproduced by the improved video signal recording and reproducing device, whether the video signal recorded through the frequency superimposition information detecting section 80 is recorded by the conventional method or not is determined. , or an improved method, and then, depending on the detection result, the selection means determines whether to select the signal processing section of the existing method or the signal processing section of the improved method. are doing. On the other hand, if frequency superposition information is detected by the frequency superposition information detection section 80, the first selection section 8
2 supplies the luminance signal to the frequency unfolding unit 101 and processes the signal along the improved luminance signal processing route.

[0023] The frequency unfolding section 101
The frequency-superimposed video signal is expanded and the expanded luminance signal is sent to a memory 91 that removes the frequency-superimposed carrier in a still image and a special reconstruction unit 102 that removes the frequency-superimposed carrier in the moving image and reconstructs a contour correction signal. supply Thereafter, the luminance signals supplied from the memory 91 and the special reconstruction section 102 are supplied to the composite luminance signal generation section 103. In this composite luminance signal generation section 103,
Although not shown, the memory section 91 and the special reconstruction section 102 correspond to the motion data of the motion signal separated from the color signal processing and motion signal processing sections.
The signals supplied from the plurality of components are combined and supplied to the adaptive peaking re-emphasis section 104. The adaptive peaking re-emphasis section 104 restores the high-frequency component to the original signal and supplies it to the other stage of the second selection section 200.

The second selection section 200 selects the memory section 91 and the adaptive peaking re-emphasis section 10 according to the frequency superposition information detection signal supplied from the frequency superposition information detection section 80.
4 and supplies the selected signal to the luminance signal output section 300. The luminance signal output section 300 includes an oversampling filter 301
and a D/A converter 302, and outputs an analog-converted signal. The oversampling filter 3
01 serves to increase the sampling rate to facilitate converting digital signals to analog signal processing. In this embodiment, the circuit for reproducing luminance signals in a compatible manner between different video systems is described only for the luminance signal processing circuit. However, the chrominance signal processing unit and the motion signal processing unit related to the circuit that maintains compatibility during the reproduction process are the same as the signal processing route of the improved video signal recording and reproduction system, and therefore their description will be omitted in this embodiment. That is, in this embodiment, only the luminance signal processing route is described in conjunction with the detection of frequency superimposition information inserted into the synchronization signal included in the luminance signal of the composite video signal reproduced from the video tape.

[0025]

[Effects of the Invention] As described above, the circuit for reproducing luminance signals in a compatible manner between different video systems is connected to the improved luminance signal processing unit in the VCR applied in the circuit according to the present invention. Therefore, video signals recorded by existing VCRs can be played back in a compatible manner. As a result, a video signal recorded by a different VCR can be played back compatible with the improved VCR without degrading the resolution of the recorded image during the recording process.

[Brief explanation of the drawing]

FIGS. 1A and 1B are block diagrams schematically showing a recording circuit and a reproducing circuit of a general video signal recording and reproducing apparatus, respectively.

2A and 2B are block diagrams schematically showing a recording circuit and a reproducing circuit of an improved video signal recording and reproducing apparatus to which the circuit of the present invention is applied, respectively; FIG.

FIG. 3 is a block diagram schematically showing a luminance signal reproduction processing circuit that maintains compatibility during reproduction between different video systems according to the present invention.

FIG. 4 is a detailed configuration block diagram of the circuit shown in FIG. 3;

[Explanation of symbols]

1 Y/C separation section 2 Emphasis section 3 FM modulation section 9 FM demodulation section 11, 36 Composite video signal generation section 21, 31 A/D conversion section 70 Luminance signal input section 80 Frequency superimposition information detection section 81 De-emphasis section 82 1 selection section 83 memory section 85 reproduction equalization section 90 frequency unfolding section 100 adaptive re-emphasis section 200 second selection section 300 luminance signal output section

Claims (10)

[Claims] Claim 1: It has an adaptive de-emphasis section, a frequency superposition section, and a frequency superposition information recording section for recording a luminance signal and a synchronization signal, and a frequency superposition information detection section for reproducing the luminance signal and synchronization signal. A video signal reproducing device for reproducing a video signal of a predetermined full bandwidth recorded in advance on a recording medium having a limited bandwidth using a video signal recording and reproducing device having a frequency unfolding section and an adaptive re-emphasis section. In a circuit for compatiblely reproducing a luminance signal between compatible different video systems, the circuit includes a luminance signal input section into which a luminance signal is input, and a luminance signal supplied from the luminance signal input section and a synchronization circuit. a frequency superimposition information detection section that receives a signal and detects whether frequency superposition information is placed on the synchronization signal; and a first selection section that selectively supplies a luminance signal according to the detection result from the frequency superposition information detection section. an improved luminance signal processing unit that processes a luminance signal using an improved video signal processing method when frequency superposition information is detected by the frequency superposition information detection unit; an existing luminance signal processing section that processes the luminance signal using an existing video signal processing method when its presence is detected, and the improved luminance signal processing section and the existing luminance signal processing section according to the detection result from the frequency superimposition information detection section. a second selection unit that receives an output signal from and selects one signal;
A luminance signal reproduction processing circuit that maintains compatibility during reproduction between different video systems, comprising a luminance signal output section that outputs the luminance signal supplied from the second selection section. 2. If a de-emphasis section for attenuating high-frequency components of the luminance signal is not installed upstream of the luminance signal input section, the de-emphasis section is connected to the frequency superimposition information detection section and the first selection section. 2. The luminance signal reproducing circuit as claimed in claim 1, wherein the luminance signal reproducing circuit maintains compatibility during reproduction between different video systems. 3. The improved luminance signal processing section includes a frequency unfolding section that desuperimposes the frequency superimposed luminance signal supplied from the first selection section, and a frequency unfolding section that desuperimposes the frequency superimposed luminance signal, and stops the frequency superimposed luminance signal. The motion data included in the video signal is received by the memory unit that removes the time-frequency folding carrier of the image and the special reconstruction unit that removes the time-frequency folding carrier of the video and reconstructs the contour correction signal. , and an adaptive peaking re-emphasis unit that restores the high-frequency component of the luminance signal supplied from the composite luminance signal generator to its original state. 2. A luminance signal reproducing circuit that maintains compatibility during reproduction between different video systems as claimed in claim 1. 4. The difference according to claim 3, wherein the existing luminance signal processing section includes a memory section that receives the de-emphasized luminance signal supplied from the first selection section and attenuates noise. A luminance signal reproducing circuit that maintains compatibility during playback between video systems. 5. The luminance signal reproducing circuit as claimed in claim 1, wherein the first selection section is composed of a switching element or a multiplexer. 6. The luminance signal reproducing circuit as claimed in claim 5, wherein the second selection section comprises a multiplexer. 6. The luminance signal reproducing circuit that maintains compatibility during reproduction between different video systems. 7. A method for compatiblely reproducing a luminance signal between different video systems when reproducing a video signal having a predetermined full bandwidth recorded in advance on a recording medium having a limited bandwidth. , a step of inputting a luminance signal processed by a standard luminance signal regenerator that processes a video signal reproduced from the recording medium through a reproduction head, and determining whether frequency superimposition information is loaded on the input luminance signal. a step of detecting, a step of selecting one of the processing routes of the luminance signal according to the frequency superimposition information, a step of processing the luminance signal along the selected processing route of the luminance signal; By including a process of selecting and outputting one of the processed luminance signals according to frequency superimposition information, compatibility of luminance signals on video tapes recorded using existing video signal recording methods is maintained. A luminance signal reproducing method that maintains compatibility during reproduction between different video systems. 8. When frequency superposition information is detected in the frequency superposition information detection step, the brightness signal processing step includes the step of widening a high-frequency component of the brightness signal frequency-superimposed on the low-frequency side of the brightness signal; generating a composite luminance signal by receiving a signal from the expanded luminance signal that has passed through a special reconstruction unit that removes folded carriers for still images and frequency folded carriers for moving images and reconstructs contour correction signals; 8. The luminance signal reproducing method according to claim 7, further comprising an adaptive peaking re-emphasis step of restoring the high-frequency side components of the composite luminance signal to the original signal. 9. The luminance signal according to claim 7, wherein when the frequency superposition information is not detected in the frequency superposition information detection step, the luminance signal processing step includes a step of attenuating noise through a memory device. How to play. 10. If there is no de-emphasis process for attenuating the high frequency side components of the reproduced luminance signal before the process of inputting the reproduced luminance signal, the de-emphasis process is replaced by the frequency superimposition information detection process. 8. The luminance signal reproducing method according to claim 7, wherein the luminance signal reproducing method is inserted between the luminance signal processing route selection step and the luminance signal processing route selection step.